“I do worry about neuro-hype,” said one commission member, Nita A. Farahany, a professor of law, philosophy, and genome sciences and policy at Duke University. Others, both on the commission and on its invited panel of experts—mostly from government agencies—tended to agree.

The pace of progress in brain science has undoubtedly been impressive, particularly in some specific areas, said Walter J. Koroshetz, deputy director of the National Institute of Neurological Disorders and Stroke. He cited electric-stimulation therapy, saying the technique, first used on human beings in 1938, has now reached the point where it can transform a patient from “a fatal depressive condition to a functional human being within a day.” Breakthroughs include using PET scans to find the area of the brain that blood flow indicates is overactive in depressed people, he said.

But even that is just the technological equivalent of “throwing current into the brain,” without a solid understanding of what exactly is happening, Dr. Koroshetz said.

More-substantive achievements, such as actually reading a person’s brain and learning their intents or their memories, appear to be far in the future, said David J. Chalmers, a professor of philosophy at both New York University and Australian National University.

Still, Mr. Chalmers told the commission, the possibilities were worth considering, as science “may well sneak up on us.”

And that is what the commission plans, as the discussion at its quarterly meeting on Tuesday in Philadelphia was the first of several public sessions it will hold on the topic before issuing recommendations requested by Mr. Obama, a spokeswoman said.

As with many ethical issues, the tried-and-true approaches may turn out to be best, said William D. Casebeer, a program manager at the Defense Advanced Research Projects Agency.

As such, he suggested sticking with “the three C’s—character, consent, and consequence”—when evaluating the ethics of a particular research question. “There is not much new under the sun in this domain” that requires a different set of principles, he said.